Analysis of endometrial cancer development

1.RAS/ER/MDM2信号转导通路在NIH3T3细胞转化过程中起关键作用。在这项研究中，我们研究了阻断这一途径对妇科癌细胞生长的影响。(1)癌细胞的MDM2水平高于正常细胞。经MEK抑制剂(U0126)处理后，MDM2水平降低，p53和p21水平升高，并通过诱导细胞早衰而抑制细胞生长。(2)MEK抑制剂对细胞生长的影响受ER水平和功能的影响。小剂量的MEK抑制剂与抗雌激素(ICI182,780)联合治疗对癌细胞的生长抑制作用比单独使用MEK抑制剂或抗雌激素更强。结论：1.siRNA下调MDM2水平可抑制癌细胞的生长。我们从人子宫内膜分离SP细胞，并对其特性进行分析。人正常子宫内膜细胞中存在SP细胞。大多数SP细胞富含CD9-CD13-组分。这些SP细胞表现出长期再增殖的特性，并产生腺样细胞(CD9阳性)和间质样细胞(CD13阳性)。人子宫内膜中的SP细胞可以作为祖细胞发挥作用。这是首次报道正常人子宫内膜细胞中SP细胞的表型。我们确定了PR-B的表达与细胞周期进展的相关性。在同步化的NIH3T3细胞中，我们发现PR-B蛋白和p27CDK抑制物水平在G0/G1期增加，而由于S和G2/M期的重新分布而减少。反义寡聚物或siRNA引起的PR-B水平的下降与p27水平的下降相对应。腺病毒感染的PR-B过表达诱导了p27的表达，抑制了细胞生长。最后，我们发现PR-B参与调控NIH3T3细胞增殖的作用不依赖于雌激素(E_2)/雌激素受体(ER)。

1. We previously demonstrated that that the Ras/ER/MDM2 pathway was critical for NIH3T3 cell transformation. In this study, we examined the effect of blocking this pathway on cell growth in gynecologic cancer cells. (1) The MDM2 level was enhanced in cancer cells compared with normal cells. Treatment with MEK inhibitor (U0126) resulted in a reduced MDM2 level, enhanced p53 and p21 levels and inhibited cell growth by the induction of premature senescence. (2) The effect of MEK inhibitor on cell growth was affected by ER levels and functions. Treatment with low-dose MEK inhibitor in combination with anti-estrogen (ICI182,780) had a more inhibitory effect on cell growth compared to treatment with MEK inhibitor or anti-estrogen alone in cancer cells. Down-regulation of the MDM2 level by siRNA resulted in the inhibition of growth in cancer cells.2. We isolated SP cells from the human endometrium and analyzed their properties. SP cells were present in normal human endometrial cells. Most SP cells were enriched in the CD9-CD13- fraction. These SP cells showed long-term repopulating properties and produced gland(CD9 positive)- and stroma(CD13 positive)-like cells. SP cells in the human endometrium can function as progenitor cells. This is the first report of the phenotype of SP cells from normal human endometrial cells.3. We determined the correlation between PR-B expression and cell cycle progression. In synchronized NIH3T3 cells, we found an increase in PR-B protein and p27 CDK inhibitor levels in the G0/G1 phase and a reduction due to redistribution in the S and G2/M phases. The decrease in the PR-B levels caused by anti-sense oligomers or siRNA corresponded to the reduction in p27 levels. PR-B overexpression by adenovirus infection induced p27 and suppressed cell growth. Finally, we showed that induction of PR-B involved in the regulation of NIH3T3 cell proliferation was estrogen(E2)/estrogen receptor (ER) independent.